標題: | A Robust Frequency Tracking Loop for Energy-Efficient Crystalless WBAN Systems |
作者: | Sung, Wei-Hao Yu, Jui-Yuan Lee, Chen-Yi 電機工程學系 Department of Electrical and Computer Engineering |
關鍵字: | Crystalless;frequency calibration;on-chip oscillator;process;voltage and temperature (PVT) variation;wireless body area network (WBAN) |
公開日期: | 1-十月-2011 |
摘要: | This brief presents a frequency tracking loop (FTL) to realize a crystalless wireless sensor node (WSN) for wireless body area network (WBAN). By tracking a remote wireless RF reference for system clock calibration, the proposed FTL allows WSNs to tolerate a large-frequency error from on-chip CMOS oscillators. Moreover, to achieve energy-efficient transmissions in crystalless, a sufficiently accurate convergence clock is required to enable burst overmegabits-per-second system throughput with minimized operation duty cycle. For the dedicated purpose, a comparison-based binary-search tracking scheme, which ensures accurate and robust convergence against noisy wireless channel, is further developed to manage the operation of FTL. The intermediate frequency back-end part of FTL is implemented in 90-nm CMOS process. Measurement results show that the FTL extends an initial tolerance of system clock error to +/- 3% and achieves a final quartz-crystal comparable +/- 50-ppm accuracy. This enables 4.85-Mb/s wireless links and improves 79% energy efficiency by RF operation-time reduction, giving a power-saved and miniaturized WSN device for WBAN applications. |
URI: | http://dx.doi.org/10.1109/TCSII.2011.2164155 http://hdl.handle.net/11536/14781 |
ISSN: | 1549-7747 |
DOI: | 10.1109/TCSII.2011.2164155 |
期刊: | IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS |
Volume: | 58 |
Issue: | 10 |
起始頁: | 637 |
結束頁: | 641 |
顯示於類別: | 期刊論文 |